1. Field of the Invention
This invention relates to a magnetic disk cartridge assembly system, and more particularly to a system for incorporating in a casing of a magnetic disk cartridge a substantially V-shaped shutter spring which urges a dust shutter in a predetermined direction with respect to the casing.
2. Description of the Prior Art
As shown in FIGS. 5A and 5B, a magnetic disk cartridge 1 is provided with a dust shutter 3 which is slidably mounted on the outer surface of a casing 2 for accommodating therein a magnetic disk, and opens and closes the magnetic head receiving opening 4 in the casing 2. A shutter spring 5 for urging the dust shutter 3 toward the closing position in order to ensure that the opening 4 closes when the magnetic disk cartridge 1 is not in use is incorporated in the casing 2. The shutter spring 5 is generally a torsional coil spring and is inserted into the casing 2 through a spring insertion opening 6 to the position shown in FIG. 5A in which it abuts against an engaging portion 7 on the casing 2 at one end and against an engaging portion 8 on the shutter 3 at the other end under its own resiliency. Since the spring insertion opening 6 is smaller in width than the distance between the ends of the shutter spring 5 when it is in the illustrated position in order to prevent it from falling off the casing 2, the shutter spring must be compressed once to clear the narrow opening 6.
Conventionally, the shutter spring 5 has been incorporated in the casing 2 by first, as shown in FIG. 6, bringing one end 5b of the spring 5 into engagement with the engaging portion 7 on the casing 2 and then pushing the spring 5 in the direction of the arrow, or by, as shown in FIG. 7, inserting the coil portion 5a of the shutter spring 5 into the opening 6 and pushing the spring 5 in the direction of the arrow.
However, in either method, the shutter spring 5 is pressed against the peripheral edge of the opening 6 to be compressed when the spring 5 is pushed in the direction of the arrow, and accordingly the L-shaped ends 5b and 5c of the spring 5 are apt to become engaged with the peripheral edge of the opening 6, causing problems in the incorporation of the shutter spring 5. This will cause failure in the incorporation of the shutter spring 5 when the incorporation of the shutter spring 5 is automated. Such a problem will also be encountered when a V-shaped spring other than a torsional coil spring is used as the shutter spring.